Oil Spill: New Study Says Bacteria Are Breaking Down the Crude

We’ve learned so many wonderful new terms during the more than four-month old BP oil spill: top kill, static kill, bottom kill, Corexit, junk shot. It’s time to add one more: Oceanospirillales. That’s that name of an order of proteobacteria that are currently chowing down on the plumes of underwater oil created by the spill—and according to a new study published today in Science, those microbes may be breaking down the oil faster than we thought.

A team of scientists led by Terry Hazen, a senior ecologist at the Lawrence Berkeley National Laboratory, deployed two ships to the waters near BP’s blown well between May 25 and June 2. They took more than 200 water samples from 17 deepwater sites, and found evidence of intense microbial activity. That’s largely a good thing—while it’s well-known from past spills that bacteria can break down oil on the surface, much less is know about deep-sea environment where the oil plumes have formed in the Gulf. Hazen’s work indicates that—despite the cold temperatures—bacteria are indeed working to neutralize the oil spill:

“Our findings, which provide the first data ever on microbial activity from a deepwater dispersed oil plume, suggest that a great potential for intrinsic bioremediation of oil plumes exists in the deep-sea,” Hazen says. “These findings also show that psychrophilic oil-degrading microbial populations and their associated microbial communities play a significant role in controlling the ultimate fates and consequences of deep-sea oil plumes in the Gulf of Mexico.”

Interestingly, the Science study shows that the bacteria are breaking down the oil without significantly reducing oxygen levels in the waters around them. That’s good news—many experts worried that a bacterial feeding frenzy on underwater oil could end up sucking much of the oxygen out of nearby water, worsening the dead zones that already show up annually in parts of the Gulf of Mexico. So far that doesn’t seem to be happening, at least according to Hazen’s research—the Science paper notes that oxygen saturation within the oil plume averaged 59%, compared to 69% outside the plume. Similar results were published in a paper by Woods Hole researchers last week in Science.

Of course, that earlier paper showed that while bacteria was breaking down oil thousands of feet below the surface of the Gulf, it was happening much slower than it would above the surface—so the oil is likely to stay underwater in some form for some time. Again, though, that doesn’t mean we know much about what damage the dispersed oil may or may not be doing to undersea life—nor do we know where the oil might be now. All of these studies—cutting edge though they are—are single snapshots in time, with no way to track the oil to where it is today. That’s one of the limitations of science done in the deep—the constant observation that’s become the norm on land isn’t yet possible. For now we’ll need to wait for more studies to clarify the picture—and the good news is there’s no shortage of new information on the way.

Update: It’s worth noting that Hazen conducted his research under an existing grant from the Energy Biosciences Institute (EBI) to study microbial enhanced hydrocarbon recovery, or bioremediation—and that EBI is funded by a $500 million, 10-year grant from none other than BP. The paper looks solid, but make of that what you will.